2.0 Analysis 2.1 General The aircraft records indicate that the helicopter was certified, equipped, and maintained in accordance with existing regulations and approved procedures. The examination of the aircraft wreckage revealed no pre-impact control failures or engine malfunction. Based on this information and on the survivors' recollections that there were no apparent mechanical problems prior to the occurrence, a control or other mechanical malfunction is not considered a likely factor in this occurrence. Similarly, in light of the known visibility and in-flight conditions, weather is not considered a factor either. Several elements specific to this occurrence affected the pilot's ability to see the unmarked power line during the low-level flight. The 3/8-inch diameter of the power line presented a very small visual target which, at a distance, even under ideal circumstances, would have been virtually invisible. The power line's support structures were difficult to detect due to the surrounding foliage. Moreover, the greyish-white power line itself blended with the ice-covered river and snow-covered surrounding terrain. Based on witness observations and survivor recollections, as well as the inconspicuousness of the power line, it was determined that the pilot did not detect the power line in time to take avoidance action. The analysis will explore several operational elements associated with this event. 2.2 Conduct of Low-Level Flight It could not be determined why the pilot descended below the normal fisheries surveillance flight altitude of 200-300 feet during the final segment of the flight without first doing a reconnaissance of the area at a higher altitude. There were no apparent operational requirements for the pilot to descend as low as he did without having first completed a reconnaissance of the area, nor did the pilot make any comments which would explain his intentions. Had a reconnaissance overflight been conducted, it is possible that the power line or its associated support structure would have been observed and the flight profile could have been altered accordingly. 2.3 Fisheries Surveillance Operations This surveillance operation involved two organizations. Each organization had its own role in the mission: Transport Canada to fly the aircraft safely and DFO to spot illegal activity and conduct related law-enforcement operations. While the two roles were quite distinct, they were closely linked and complemented one another. Despite the relationship between the two roles, and the differences between them, the agencies did not meet to discuss operational requirements or to reach agreement on in-flight procedures. In the case of the accident flight, had standard operating procedures been in effect for such elements as altitudes, airspeeds, and reconnaissance overflights prior to descents to low altitudes, the risks inherent within the mission would have been mitigated, ensuring a safer and more predictable operation. 2.4 Marking of Power Line This power line was erected prior to 23 February 1940, and this occurrence was the first reported aviation accident related to the line. The fitment of markers on the power line would have made the line more visible and increased the possibility of it being detected by the pilot. Had an aeronautical study been conducted on this specific power line, it is likely that the power line would not have been marked for several reasons. The height of the power line above the Margaree River was well below the altitude expected to be flown by helicopters or fixed wing aircraft. In addition, that portion of the Margaree River is not on a visual flight route normally flown by helicopters or other aircraft, nor is the power line in the vicinity of an aerodrome or heliport. 2.5 Wire Strike Protection Systems As ACAC 0020 recommends, the installation of WSPS equipment on helicopters engaged in low- level operations can only enhance the safety of the operation. In this accident, the helicopter contacted the wire in a position where WSPS has been demonstrated to be effective. Had this helicopter been fitted with a WSPS, it is very likely that the power line would have been cut. In that event, the outcome of the occurrence would likely have been considerably less severe. 2.6 Passengers - DFO Surveillance Flights The carriage of non-essential passengers is not specifically addressed in the TC HFOM; however, in general, passengers may be carried in the helicopter when their presence will not interfere with the purpose of the flight. Notwithstanding the hazards posed by the law-enforcement nature of the flight, helicopter fisheries surveillance flights require that the helicopter be flown at low altitudes for extended periods. The carriage of non-essential passengers on such high-risk, low-level operations unnecessarily exposes additional persons to the dangers inherent in such operations. 3.0 Conclusions 3.1 Findings The pilot was certified and qualified for the flight in accordance with existing regulations. The helicopter was certified, equipped, and maintained in accordance with existing regulations and approved procedures. There was no evidence of pre-impact airframe failure or engine malfunction. The power line was not marked nor was it required to be marked by regulations. The helicopter contacted the power line in the area of the bottom of the main windscreen. No operational requirement or reason could be found that would explain why the helicopter was being flown as low as it was without first having overflown the area to ensure that the area was free of wires or other obstacles. There was no formal agreement in place between TC and DFO establishing the terms of reference of the operation, nor was there communication between the two agencies regarding the risks associated with this type of operation. No standard operating procedures for this type of surveillance operation were available to the pilot, nor was any awareness training provided. The helicopter was not equipped with a WSPS, nor was one required by regulation. Had this helicopter been fitted with a WSPS, it is very likely that the power line would have been cut. The ELT became detached from the helicopter during the crash sequence and was found on the ice in the OFF position. The pilot was not wearing his helmet during the flight. 3.2 Causes The pilot did not see the power line in time to take avoidance action. The pilot's decision to conduct the portion of the flight over the river at low altitude without having first completed a reconnaissance of the area for obstructions, and the absence of clearly defined procedures on the conduct of fisheries surveillance flights were contributing factors in the accident. 4.0 Safety Action 4.1 Action Taken 4.1.1 ELT Arming The ELT was found intact on the river surface with the function switch in the OFF position and intact. The absence of damage to the switch and the area surrounding the switch led to the conclusion that the ELT was in the OFF position prior to impact. It could not be determined when the OFF selection had been made. Transport Canada pilots have been reminded to follow the Standard Operating Procedures regarding the confirmation of the ELT armed switch location. During a check, or training flight, the position of the switch would be a debriefing point if it were not checked. 4.1.2 Passengers - DFO Surveillance Flights Helicopter fisheries surveillance flights require that the helicopter be flown at low altitudes for extended periods. The carriage of non-essential passengers on such high-risk, low-level operations unnecessarily exposes additional persons to the dangers inherent in such operations. Transport Canada has issued instructions to preclude the carriage of passengers on board aircraft conducting specialty operations. 4.1.3 Wire Strike Protection Systems In this accident, the helicopter contacted the wire in a position where WSPS has been demonstrated to be effective. The Board notes that devices are being developed to warn crews of wires and cables. The installation of WSPS on all Transport Canada's helicopters will be completed within 15 months. By December 1995, each region will have at least one helicopter equipped with a WSPS.